Tansley Review No. 115

Abstract

Sexual reproductive development is a crucial stage in the life cycle of higher plants as any impairment of the processes involved might have significant implications for the productivity of crop plants and the survival of native species. There is considerable evidence that exposure to ozone, even at current ambient levels in many industrialized countries, reduces grain and fruit yields and adversely affects yield quality. It is also well established that sensitivity to ozone may differ not only between species, but also between cultivars and populations of individual species, and that the impact of exposure is highly dependent on ozone concentration and the duration and timing of exposure. However, few studies have attempted to distinguish between the direct effects of air pollutants on reproductive development, and indirect effects mediated by injury to the vegetative organs and associated changes in the supply of assimilates and other essential resources to support reproductive growth, or the levels of endogenous growth regulators. This review considers the impact of ozone on the reproductive biology of agricultural and native species, and examines its direct effects on specific reproductive processes. The extent to which compensatory responses redress the adverse effects of exposure is also explored, with particular reference to recent studies of Brassica napus (oilseed rape), Brassica campestris (Wisconsin Fast Plants), Plantago major (greater plantain) and Triticum aestivum (wheat).

Closing the global ozone yield gap: Quantification and cobenefits for multistress tolerance

“…Traits associated with reproductive organs such as panicles or pods are of primary importance in breeding, although the effects of ozone on these organs may be rather secondary, that is caused by foliar responses that limit assimilate acquisition (described above) or effects on flowering and pollen viability (Black, Black, Roberts, & Stewart, 2000). Yield losses due to ozone have been ascribed to various yield components in different crops, including reductions in individual seed weight, reduced spikelet number, enhanced spikelet fertility, and reduced panicle or pod number (Ainsworth, 2008;Feng, Kobayashi, & Ainsworth, 2008;Morgan, Ainsworth, & Long, 2003), with associated reductions in harvest index (e.g.…”

Short-term physiological effects of smoke on grapevine leaves

“…The advantage of using these species as fuel is that they are likely to be a significant contributor to smoke emissions in the winegrowing regions of California as they occupy a sizeable area of the surrounding vegetation or as plantations and windbreaks (CalFlora 2012). Tasmanian Bluegum is a common forest tree in Victoria and Tasmania (Boland et al 2006) and is therefore also expected to be a major contributor to smoke emissions during wildfires in these Australian states. Leaves from both species were collected from small plantings of mature trees on the University of California, Berkeley campus.…”

Effects of ozone exposure on ‘Golden’ papaya fruit by photoacoustic phase-resolved method: Physiological changes associated with carbon dioxide and ethylene emission rates during ripening

“…2(a) and 2(b), the chlorophyll band near 680 nm is missing; it is likely that the latter was probably destroyed by the action of ozone which accelerates the maturation. 29 Only carotenoids [ Fig. 2(c)] and cuticle [ Fig.…”